In a new documentary, "How to Make Money Selling Drugs," Eminem is opening up about his scary drug abuse, revealing that he almost died during one overdose.

The rapper, who entered rehab for sleeping pill addiction in 2005 and addressed the problem in his 2010 album "Recovery," has admitted in the past to taking 10 to 20 Vicodin (painkiller) pills daily. "Valium, Ambien, the numbers got so high I don't even know what I'm taking," he told Vibe magazine after his rehab stint.

Now, in the new documentary, the 40-year-old reveals that his prescription drug abuse nearly killed him. "My bottom was going to be death," he says in the film excerpt on YouTube. Recalling the first time he had Vicodin, he explained it was a "feeling of 'Ahhh,' everything was not only mellow, but didn't feel any pain. It just kind of numbed things."

The Detroit native said that it was hard for him to realize that he had a problem since he wasn't abusing drugs like crack or heroin.

"I don't know what point exactly it started to be a problem, I just remember liking it more and more," he explained.

If friends tried to tell him to get help, "I would say, 'Get that fucking person outta here, I can't believe they said that shit to me,'" he recalled. "'They don't know nothing about my fucking life, are they out of their fucking mind? I'm not out there shooting heroin, I'm not out there putting coke up my nose, I'm not smoking crack; I literally thought I could control it."

The abuse did catch up to him, though, as he reveals his scary brush with death when he was hospitalized following an overdose.

"Had I got to the hospital about two hours later, I would have died," he said. "My organs were shutting down. My liver, kidneys, everything. They were gonna have to put me on dialysis, they didn't think I was gonna make it."

Once leaving the hospital, Eminem says that he didn't sleep for three weeks and relapsed a month later. "I remember just walking around my house and thinking every single day, like, I'm gonna fucking die. I'm looking at my kids, and like, I need to be here for this."

Explaining that he had to regain his motor skills and talking skills, the Grammy-award winner shared that's come a long way since his days of drug abuse.

"It's been a learning process," he said. "I'm growing. I just couldn't believe that anybody could be naturally happy or naturally function or be just enjoying life in general without being on something."

He added, "So I would say to anybody, 'It does get better, you know. It just does.'"

Eminem is dad to Hailie Jade Scott, 17, whom he had with ex Kimberly Scott. They divorced in 2006. He also has adopted two other daughters: Alaina "Lainie" Mathers, the child of Scott's sister, and Whitney, Scott's child from a previous relationship.

The film, which opened on June 29, also features interviews with Russell Simmons and Woody Harrelson.